The invention relates to a new antibiotic. More specifically, it relates to the antibiotic equisetin produced by Fusarium equiseti NRRL 5537.
It is known that various species of Fursarium produce toxins which are implicated in mycotoxicoses in several areas of the world. Burmeister et al. [Appl. Microbiol. 23: 1165-1166 (1972)] incubated 136 strains of Fusarium sp. to determine their capacity to produce T-2 toxin.
The inventor has now discovered that one strain, F. equiseti NRRL 5337, produces a substance that strongly inhibits several genera of gram-positive bacteria.
Although many antibiotics and mycotoxins are produced by strains of Fusarium species, none have the biological activity and the chemical properties of the antibiotic elaborated by F equiseti NRRL 5537. The principal fusariotoxins: zearalenone [Mirocha et al., Microbial Toxins, Vol. 7, Kadis, Ciegler, and Ajl (ed.), Academic Press, Inc., New York, 1971, pp. 107-138], butenolide [Yates et al., J. Agr. Food Chem. 17: 437-442 (1969)], fusariogenin [Joffe, A. Z., Microbial Toxins, Vol. 7, supra, pp. 139-189], or the 12,13-epoxytrichothecenes [Bamburg et al., Microbial Toxins, Vol. 7, supra, pp. 207-292] either lack or only exhibit weak antibacterial properties. Of the antibacterial metabolites produced by the genus Fusarium, the enniatins [Korzybski et al., Antibiotics: Origin, Nature and Properties, Vol. 2, Pergamon Press, Oxford, England, 1967, pp. 1310-1325] are most nearly like the antibiotic of F. equiseti NRRL 5537 in their microorganism-inhibition spectrum. Both the enniatins and the product of F. Equiseti NRRL 5537 inhibited Mycobacterium pheli, Bacillus subtilis, and Staphylococcus aureus in vitro at concentratons below 1 .mu.g./ml. However, the enniatins and equisetin are grossly different in their chemical and physical properties.